misfiring

[DZA]

This is for a 2003 A4 3.0L

I replaced the coil for the 3rd cylinder b/c of a P0303 code (Cylinder 3 Misfire detected) but I also got a P0300 (Random/Multiple Cylinder Misfire detected). They are both intermittent.

If it's random/multiple on the second code, how do I know which cylinder might have a problem?

Is intermittent worse than an all the time misfire? Couldn't intermittent basically be anything?

I'm hoping that the codes will clear and just stay away but if they are still there, any one have any suggestions? I'm hoping things are just a little dirty-dirty.

By the way, the car seems to ride perfectly fine. Nothing seems to be wrong. Even if it was intermittent... wouldn't I feel some thing at least some of the time? I MIGHT feel a slight stumble around 4000rpms but it might be in my head b/c i'm looking for something wrong.

Isn't it possible to have random misfiring if there is air getting passed the airflow sensor and/or vacuum leak some where? I had that before in my galant when I put my car back together when it was too dark and my MAF wasnt connected tight BUT you could feel it chugging and stumbling.

Thanks for the help.

[DZA]

Yes, i'm about to reply to my own post b/c i learned some things and it might help some one else.

Originally Posted by DZA

If it's random/multiple on the second code, how do I know which cylinder might have a problem?

My other trouble code told me which cylinder was the problem. Replacing the coil on the 3rd cylinder also cleared the random/multiple code

Originally Posted by DZA

Is intermittent worse than an all the time misfire? Couldn't intermittent basically be anything?

Its just a pain in the butt b/c the car doesn't feel like anything is wrong. I essentially randomly checked for codes. The answer to my second question there is yes but apparently the best start is the coil b/c it was only 40 bucks and took 20 minutes to replace.

Originally Posted by DZA

I'm hoping that the codes will clear and just stay away but if they are still there, any one have any suggestions? I'm hoping things are just a little dirty-dirty.

Apparently, plugs, wires, airflow sensor being bad or leaking and not checking all the air. Start small and go from there, worse can scenerio, you end up with new toys to put on your car, lol

Originally Posted by DZA

By the way, the car seems to ride perfectly fine. Nothing seems to be wrong. Even if it was intermittent... wouldn't I feel some thing at least some of the time? I MIGHT feel a slight stumble around 4000rpms but it might be in my head b/c i'm looking for something wrong.

Apparently not b/c i felt no difference. The stumble was probably in my head.

Originally Posted by DZA

Isn't it possible to have random misfiring if there is air getting passed the airflow sensor and/or vacuum leak some where? I had that before in my galant when I put my car back together when it was too dark and my MAF wasnt connected tight BUT you could feel it chugging and stumbling.

Apparently, if the airflow sensor is bad, you'll have several cylinders appear bad, not just 1.

[shedpress]

WELCOME TO THE FORUM DAN! post some pics of your super sick VOTEX'd out a4, yo.

so you came down to the conclusion that it's something with your air flow sensor? So maybe clean your MAF?

[DZA]

Originally Posted by silverGTI

WELCOME TO THE FORUM DAN! post some pics of your super sick VOTEX'd out a4, yo.

so you came down to the conclusion that it's something with your air flow sensor? So maybe clean your MAF?

super sick, eh? lol. i'll have to get some better pictures... i just have 1 of its tail hosted on the internet. we should get yours, my bros and my car together for some pictures by the way (you'll have to actually wash yours first, hah)

the MAF is fine or it would have still thrown some engine codes... UNLESS the coil was fine and I just happened to fix any leaks to the MAF in the process of putting things back together. Even then, the MAF is fine and it could have been a leak. A bad MAF or air leaks feels horrible. I think I could feel that instead of seemingly nothing wrong. My GTZ had a loose fitting around the MAF before and it felt like I was tapping the gas pedal.

I still want to know how replacing the coil had the headlight/taillight warning light shut off for a day or two.